Display refrigerator



Dec. 19, 1933. v P WARREN DISPLAY REFHIGERATO Filed July 9, 1932 4 Sheets-Sheet l DCC. 19, V. p WARREN DI SPLAY REFRIGERATOR Filed Juiy 9, 1952 4 sheets-sheet 2 im crm/4% DCC. 19, V. l WARREN DI SPLAY REFRIGERATOR Filed July 9, 1932 4 sheets-sheet 3 V//Q/z. P. WA RRE/v Wmfmwmm Dc. 19, 1933. v P, WARREN 1,939,800

DISPLAY REFRIGERATOR Filed July 9, 1952 4 sheets-sheet 4 ffy# 45 46 Y Sme/rdm 12+' V//eG/L R WAr/ez-:N

1B cold air descending in the center toward the the ice tank;

Patented Dec. 149V, 1.933 1 y l l y ,UNITED STATES PATENT #ol-FICE l 1,939,800 DISPLAY REFRIGERATOR Virgil P. Warren, Atlanta, Ga. Y Application lJu1y.9,` 19st. serial No. 621,700. 3 Claims. (Cl. s2-37.1)

This invention relates to display refrigerators as the following description of a preferred `and Y and proposes an improvement in` refrigerators practical embodiment thereof proceeds.

of the showcase lll/Pe employing ice and brine In the drawings which accompany .and form as the refrigerant. 1 Y a part of the following specification and One of the objects of the invention is to prothroughout the several figures of which, the 60 vide a display refrigerator which in itsV novel same characters of reference have been emconstruction lobviates theruse of the customary ployed to designate identical parts: side ice bunkers, and substitutes instead an ice Figure 1 is a perspective View of a refrigertank, centrally arranged within the showcase ated showcase embodying -the features vof the in the upper part thereof and preferably expresentf invention; f

tending throughout the length of the `refrig- Figure 2 is a vertical cross section of the same; erated chamber. g Figure 3 is a cross section through the ice By this arrangement a natural convection cirtank; culation of air is set -up and maintained, the Figure 4 is a perspective view of a portion of 'l0 bottom ofthe case and the warmer air arising Figure 5 is a vertical section taken along the adjacent the walls of the showcase, minimizing line 5--5 of Figure 3; the rate of heat exchange with the outer atmos- `Fir-lures 6 and 'l are detailed Views in `perphere, and thus enhancing the efficiency of the Spective of braces used to support Vand retain showcase, the absence of side bunkers vpermitting the shape o f the screen baille which extends 75 the display space to extend throughout the en'- longtlldnally flOIlgv the middle 0f the ice tank; pire "length 0f the showcase, Figure 8 is a perspective view showing in de- Another object of the invention is the protail, 011e end 0f the drip tlOllgh; vision of the refrigerating tank in a focal posi- Figure 9 `S a llOlZOIltal SeCtiOn 'through a tionto produce the efiicient air circulation above Dertien 0f the ShOWCaSe ShOWng means for de- 80 referred te, seid tank being adapted to be hydratine the cells between thc spaced panels; charged with broken ice and salt and constructed Figure 110 is a Vertical section showing the so as to cause the relatively warm air to flow Seme; Y Y through the interstitial spaces betweenthe ice Figurell iS a hOlZOntal Section lthrough the lumps, and in contact with the ice, whereby .the Selective dehydlatng ValVe; and 85 airis cooled, humidied and filtered, and.de. Figure 12 4iS a Section teken alODg the line scends through a longitudinal opening at the .bot- 12-12 0f Figure 11. tom .of the tank, the air in the filtering being Q'Refell'ng 110W n detail t0 the Several gures. cleansed of undesirable food ilavors, and rethe numeral l represents in general 'the showturned to the refrigerated chamber in .optimum Case Comprising the Usual Side. tol? and back 90 condition as regards low temperature and 'high Wells .and the fIODt display Window 2, which as humidity. y i shown in Figure 9, is for purposes of improved A vfurther object of the'invention is the proheat insulation, fcrmedcf a plurality `cf glass vision of means for automatically preventing Panels 3, :set into suitable framework, repre- 40 frost condensation on the outer surfaces of the Selted by element? 4 and 5 and defining With 95 ice tank, whereby through the avoidance of ice Sad framework au Geus 6 nd 7 The back insulation,`the refrigerative eilciency of the ice Wan. 9i the Casals provldefl Wlth Smtable doors tank is further improved l l 8, giving access to the refrigerated chamber and Still another object of the invention is the ghogarably formed as ,af hmged'hd efficient utilization ef the liquid brine `duschen-ee g' 100 o, th' :th h F- from the brine ,tank in the further cooling -of falten ihfvfc tietaltefthi the refrigerated chamber, l

. preferably extends throughout the length of the Another Object 0f the lm {enlln ISlhe vPIOV- showcase.V It will be observed from Figurel that S1011 0f a refrigerated ShOWCaSe 0f universal 00ndue ,tothe absence of the side ice bunkers which 105 struction to the extehtthatit may be COnVered were `indispensable vto the older type of. refriginto an eflicent mechanical refrigerator, Simply erated showcases, the display space occupies removing the reticulated partition and vinstalling `4substantially the entire length of .the showcase. a mechanical coil within the ice tank. l I An intermediate shelf `1l is shown and `a shelf Other objects ofg'the4v invention will appear 112 at the bottomof the showcase, but it is to `be 11.0

center of the case.

blower.

understood that the location of these shelves is optional and that one or both may be omitted if desired.

In the well known side bunker type of refrigerated showcase, it was customary to charge the bunkers with a mixture of ice and salt, thereby producing a cold atmosphere in the bunkers which was compelled to travel laterally toward the middle of the. showcase in order to refrigerate the same properly. Since a lateral, that is to say, ka horizontal flow of cold air is not in a natural convection direction, it is obvious that this flow was either very sluggish or else had to be induced by mechanical means such as Aa. By arranging the ice and salt tank`l in the top of the refrigerated chamber, the cold air eventuating therefrom descends naturallyY downward along the middle of the case, and the displaced warmer air ascends along the Vwalls of the showcase.

Referring to Figures 3 and 4, it will be noted that the" ice tank isprovided with a median slot 13 extending longitudinally along its bottom and that from the sides of said slot a wire screen baffle 14 arises, preferably'substantially to the height of the tank. Saidlscreen baille is preferably formed by folding a piece of wire' screen into an inverted V-shape, and it may be secured by flanging the bottom edges thereof as is indicated by 15 and securing the flanged portions under strips 16, the latter being'securely Ybolted to the bottom of the tank. The screen baille is supported at the ends of the tank by a bent metallic brace 17 shown in'Figure 6, and at intermediate points it is supported by the rigid spacers' 18. I

It will be understood that the details of construction ofthe brace 17 andY spacers 18 are matters of but little moment to the present invention, and that numerous equivalent variations in the form of these elements maybe made without transcending the scope of the invention.

The ice tank 10 is designed to be charged with lumps ofl ice on both sides of the baffle 14,v interspersed with sufllcient salt to produce the desired refrigerating temperature. Figure' 2 shows that the ice tank is supported in spaced relation as indicated by the reference character 19 from the top of the refrigerated chamber and that it is spaced from the side walls ofthe showcase providing a path for the circulation of air upward along the front and back of the showcase down into the ice tank, through the interstices in the ice, through lthe screen baille 14 and out through the slot 15. 4

...Since said slot is above the middle of the refrigerated chamber, the cold air flows downward to the bottom of the refrigerator in the center thereof and in cooling relation to the underlying shelves 11 and 12. By Virtue of the dropping of the cold air through the center of the tank to thev bottom of the case, the warmer. air comes in contact with the glass panels and with the walls of the case, this being particularly important with relation to the temperature at the bottom of the case, as with ordinary refrigeration, the bottom is subjected to the most extreme cold while in the present invention the circulation of. the air has the'tendency to return by way of the side walls to the top ofl thecase, again filtering through the ice and down the kBy having the warmer currents flow against the glass and side walls. there is a smaller temnerature Vdifferential between the air inside and'v that outside of the case and therefore, there is a less heat transfer so that the desired temperature of the refrigerating chamber can be produced and maintained with a much higher temperature of the refrigerating medium. This Oilers a considerable saving in ice and allows an extremely high efhciency in the meltage of the ice and also eiects economy in the use of salt since a much less quantity of salt is required to produce the low temperature which is found sufiicient to produce the desired temperature, than was possible in the older types of refrigerator, in'which a lower temperature of the ice tank hadto be maintained.

A drip trough 20 is arranged beneath the slot 15 andV catches the brine resulting from the meltage of the ice and the dissolving of the salt. The bottom of the drip trough slopes as indicated `at 21 in Figure 5. At the lower end is a drain pipe 22 which discharges into a brine settling basin 23 of some capacity, having a baille 24 extending downwardly and terminating adjacent the bottom of said basin. The drain pipe 22 discharges on one side of this baille andron the other side is an overflow pipe 25/extending to a point near the top of the settling basin. Thus the brine is compelled to flow beneath the baille 24, all iloatable matters coming to the surface and matters which will not float collecting in the bottom of the settling basin; The over-- flow pipe leads into the anterior end 26 of Va coil 27, the limbs of which are preferably arranged in labyrinthine manner adjacent to the shelf 11. A discharge pipe 28 arranged in the form of a trap is' connected to the posterior end of the coil 2'7Iand is so determined that the efiluent brine is no colder than the refrigerator temperature.

The drip trough is made suillciently wide to catch any dew which may condense on the outer wall of the ice tank and which may flow down the depending flanges 36 formed at the lower edges of the bottom wall of the tank and which overlie the said drip. trough. In order to prevent condensed moisture from the drip trough being precipitated upon thefoodstuils on the shelves below, a trough shaped baillc37 is provided, underlying the driptrough and inclined slightly toward the settling basin 23 into which it drains. vThis baille is preferably supported in spaced relation to the drip trough by means of angle bars 38, fixed to the underside of the drip trough andv extending longitudinally, and short spacingblocks 39, preferably of Wood or other insulating material. Free circulation of air between the drip trough and baille, together with insulated relation of these two elements, maintains a temperature differential between them that keeps thetemperature of he baille above dew point.

For the prevention of frost accumulation upon the outside of the ice tank, with the 4attendant annoyance of its melting and dripping upon the foodstuffs, the ice tank is made double walled, the Walls Abeing constituted by two metal sheets 30 and 31 spaced apartl at intervals by short blocks 32 of wood or, other suitable insulation material, forming a jacket which communicates along its lower edge with Vthe air eduction slot 15. The 'ends of the jacket thus formed are closed by the abutment of Ythe'ice tank against f the Yendwalls of the showcase or by suitable illler pieces not shown.Y The top edges of said 'Y jacket are closed and supported by continuous longitudinalwooden stringers 33. In order to assure the substantial absence of thermal coniso ist

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ductivity between the inner and outer walls of the ice tank, the stringers 33 and the blocks 32 are secured in place as shown in Figure 3 by bolts 34, Vthe heads of which are countersunk, as shown at 35, so as to be out of contact with one of the walls, the bolt passing through and securing the other wall in place.

The low temperature produced by the ice and salt in the ice tank reduces, the temperature of `of the jacket.

the air in the jacket between the walls 30 and 31, densifying said Vair and therefore, increasing its weight so that by convection it tends to descend and spill out of the lower longitudinal open end This produces a partial'vacuum within the jacket providing suiiicient insulation to maintain high enough temperature on the outside casing to prevent ice and frost formation.

Means are provided to prevent moisture condensation on the multiple panes of the glass panel 3. This means is the sameas forms the subject matter of my Patent No. 1,856,008, granted April 26, 1932, and comprises a casing 43, attached at any convenient point and preferably to one side of the showcase, said casing containing a dehydrating chemical such for example as calcium chloride. Said casing is connected, through selectively `operable distributing valves 44, with air circulating conduits 45 and 46, each of which includes one of the window spaces in its circuit.

A blower 47 intercalated in the common limb 48 of the circulating conduits produces air circulation through the drier and though either or both ofthe window spaces, drying the air and thereby preventing condensation of moisture or frost on the window panes. The blower may be operated periodically when required.

In view of the scientific coordination of the various features of this invention, and the consequent high thermal efiiciency thereof, it is possible to maintain a showcase atmosphere as low as 20 F. or lower, with a variation of not more than 3 or 4 in the temperature at the top and bottom of the case, with a minimum quota of salt and a surprisingly low ice meltage.

It is, of course, understood that the specific details of construction as illustrated and described are merely exemplary of a preferred embodiment of the invention and not as limiting the scope of the invention as claimed.

What I claim is:

1. Refrigerator comprising walls forming a said eduction opening.

chamber, an ice tank extending longitudinally in the upper part of said chamber having an air eduction Vslot in its bottom remote from said walls, a screen partition upstanding in said tank and bridging said slot, a drain trough beneath said slot, said tank being arranged in a focal position to determine an air circulation upward adjacent said walls, over and through the ice in the ice tank through said screeny partition, and down through said eduction opening, said drain trough spanning the width of said eduction opening and functioning as a baiile to divide the downward air circulation, in effect increasing the width ofthe air current, a settling basin into which said trough discharges, and a coil receiving the discharge from said settling basin and conducting it circuitously in a substantially transverse plane through said chamber.

2. Refrigerator comprising walls forming a chamber, an ice tank extending longitudinally in the upper part of said chamber having an air eduction slot in its bottomrremote from the walls of said chamber, said ice tank being, arranged in a focal position to determine an air circulation upward adjacent said walls, over and through the ice in the ice tank, and down through said eduction slot, said ice tank being double walled for the avoidance of frost on the outer surface thereof, the space between the walls of said ice tank being isolated from said chamber except at the bottom where said space opens in the path of the descending `air circulation adjacent said eduction slot, for maintaining an insulating partial vacuum within said space induced by the gravital descent of the dense air within said space and its entrainment inthe descending air circulation.

3. Refrigerator comprising walls formingl a chamber, an ice tank in said chamber having 115 an air eduction opening in its bottom, remote from the walls of said chamber, said ice tank being double walled for the avoidance of frost on the outer surface thereof, the space between the walls of said ice tank being isolated from 120 said chamber exceptA at the bottom, for main-` taining an insulating partial vacuum within said space induced by the gravitational descentk of the dense air within said space, entrained in the downward current of air passing through 125 VIRGIL P. WARREN. 

